In the area of door sealings, hose connections and low water zones of mechanical dishwashers, that is, where the surfaces of the interior of the dishwasher are not exposed to the direct and intensive operating pressure spray of the cleaning liquor, soil is frequently deposited in the course of time. This soil consists mainly of finely-divided fatty food residues.
Occasional unavoidable troubles in the ion-exchange system of the dishwasher water supply, which serve to soften the water used, or the consistent underdosing of the dishwasher detergents by the user also cause increasingly deposits of a mixture of calcium from hard water and residues of the detergent on the inner surfaces of the machines.
Partly so-called "tempering colors" are formed, as rainbow-colored discolorations of refined steel parts of the dishwasher or of dishes of refined steel are called.
These deposits represent an undesired nutrient soil for rotting processes, which manifest themselves by an unpleasant odor, particularly when the dishwasher is opened after it has not been used for a long time. Beyond that, hose and sealing materials, particularly at the door, are damaged by prolonged action of these soil deposits.
The commercial powdered alkaline or acid dishwasher detergents or clean rinse agents are not or only inadequately suitable for cleaning the so-called "problem zones" of dishwashers where soil is particularly likely to be deposited. These dishwasher detergents are dose into the washing and rinsing cycle of the dishwashers and are dissolved therein; however, the soiled regions are not touched at all or only briefly by them. It is, therefore, necessary to clean these zones manually. The detergents used for cleaning the dishes are unsuitable for this purpose, since they irritate the skin. Commercial cleansers for hard surfaces are not suitable either for these special applications, since they contain generally high-sudsing tensides or surface-active compounds whose residues can lead to various troubles in dishwashers.